18 May 2016

Energy Burned at the Gym

I love getting lots of exercise, especially my morning workout at Ponds Forge.  When I go too long between workouts, as happened with my recent arm break, I don't feel very good, sluggish, in fact.  Now that my arm is mostly mended, I'm back to a regular three-to-five visits to the gym each week.  My workout begins with 60-75 minutes of cardio, followed by weights.  Like anyone else who likes to use a gym on a regular basis I have certain goals I strive to attain.  My goal for cardio is to average a burn of 10 Calories per minute, and I have to push myself a bit to keep that average up for an hour or more.  So what does burning 10 Calories per minute really mean, and why do I capitalize "Calories"?

If you've ever used, for example, a stationary bike in a gym, you've noticed that all modern bikes have a screen that shows energy burn, typically in Calories.  How does the bike know?  I enter my age and mass before starting my bike work.  The machine doesn't know my gender, my height, or my level of physical fitness.  My heart rate is determined by an electronic sensor in the handle I hold while biking, but that's it for biometric data.  So general population statistics must be used in the determination of energy burn.  That's a lot faster than having to enter gobs of information before exercising, some of which we probably wouldn't want to enter anyway.  And besides, how accurately do you really need to know how many calories you burned?  You certainly want the number to be reasonable.  After all you don't want to spend an hour on a bike and be told at the end of that hour that you burned 6 Calories.  The idea is to provide a reasonable estimate, which mostly serves to help me set goals.  Tomorrow I'll burn five more Calories!

How much energy do 10 Calories represent?  Well a "calorie" is an energy unit that scientists found useful while doing calorimetry (note the similarity?).  The "thermochemical calorie" is defined to be exactly 4.184 joules.  Other definitions of "calorie" involve how much energy is needed to increase water's temperature a certain amount at various starting temperatures.  All those definitions give approximately, 1 cal = 4.2 J.  The "kilocalorie" is what we think of as a nutritional calorie.  Often called a "large calorie," the unit is written "Calorie" with a capital "C" to distinguish it from a normal calorie.  Nutritional labels that state how many "Calories" are contained in food really mean "kilocalories."  Here in England, I often see "kilojoules" or kJ on food packages.  That means 1 kcal = 1 Cal = 4.2 kJ (good to two significant digits).  My per minute burn goal of 10 Calories thus translates to about 42 kJ per minute.

Let's suppose I bike for a full hour and I'm told that I've burned exactly 600 Calories, thus achieving my 10 Calories/minute goal.  The computer determined the energy burn from average population statistics, as I've mentioned, and from simple physics.  It's not hard to calculate how much work is done with each turn of the bike's wheel at a given resistance setting.  To check the bike's accuracy in determining my energy burn, I prefer to work with power, which, in this case, is the rate at which energy is burned.  Burning 10 Calories per minute turns out to be equivalent to an average power of 697.8 watts.  Instead of working with all those digits, let's just round up and say that 10 Cal/min corresponds to 700 W.  Is that a reasonable power output?  Not for me!  During last year's Tour de France, the black sticks you saw on bikes determined, among other things, a cyclist's mechanical power output.  A few cyclists published their power data, and for some of the big climbs, power outputs were in the range of 300-400 W.  Do I seriously double the power output of an elite cyclist at the gym each morning while I'm watching news on the screen in front of me?  No!

So what to make of 700 W?  Well the bike's computer is trying to tell me how much energy I burned, not my mechanical energy output.  Energy conversions in the body and with muscle actions, as with car engines, are not even close to being 100% efficient.  Muscle efficiencies depend on which muscle groups are used.  Some exercise equipment may even add the energy burned from normal metabolic processes that take place, even when we're not on a bike.  In my Tour de France research, I've used an average efficiency of 20% to estimate how much energy a Tour de France cyclists burns for each stage.  Suppose the bike I use in the morning skips my normal metabolic burn and uses 25% for its efficiency conversion calculation.  That means my power output was just 175 W.  Now that's more reasonable!  At that power output, I'm about half a Tour de France cyclist on a steep climb.  I could output more power, but I couldn't maintain that power output for an entire hour.  That Tour de France cyclists can output 300-400 W for a half hour or more is testimony to just how fit they are.

Next time you're in the gym, note your energy burn on the machines that provide such information.  Then calculate your average power.  See how close you get to an elite athlete like a Tour de France cyclist.

16 May 2016

A Weekend in the 12th Century

Desperately needing a couple of days away from work and normal home routine, my family decided to spend this past weekend along the southern edge of the North York Moors.  We became members of English Heritage when we were in England for my first sabbatical seven years ago; renewing our membership was one of the first things we did after getting settled in Sheffield for this sabbatical.  We've been all over the UK looking at marvelous monuments to history.  Four such English Heritage monuments took us back to the 12th century while up north this past weekend.

After the Norman Invasion of England in the 11th century, new castles and abbeys were built.  Castles often had the motte-and-bailey fortification scheme.  Those are the most fun for my younger daughter and me because we love to climb the earthworks and "attack" the castles.  Playful today for sure, but we do get at least a sliver of a glimpse as to what it would have been like to make an attack on a motte-and-bailey castle.

Because the places we visited were not so easy to get to via train and bus, we rented an automobile.  It was my first time driving in England, though I had driven in Ireland seven years ago, so it wasn't my first time driving on the "wrong" side of the road with the steering wheel on the "wrong" side of the car.  My wife was great about reminding me to "Keep left!", but it didn't take long to get used to driving here.  The circuitous loop we had to take to get to a petrol station at a services exit is a story for another day.  For now, I'll mention that it was a thrill driving up to the North York Moors.  We saw many large fields of rapeseed, which provided spectacular yellow next to the lush greenery.

Our first stop was to an abbey that I'd wanted to see for a long time, Rievaulx Abbey.  The magnificent structure is located in an idyllic setting:  peaceful with beautiful vistas.  The photo I took below hardly does the monument justice (click on the image for a larger view).
The architecture blew us away.  There was so much to see.  We learned that Henry VIII dissolved the abbey in 1538, a fact mentioned early on the abbey's Wikipedia page.  English Heritage does a great job with images scattered throughout that give a sense of what life was like when the monuments were in their heyday.  Check out the reconstructed image of the refectory on the left and the actual remains of the refectory (upper floor) in the photo on the right (click on the image for a larger view).
It was wonderful standing where I took the photo on the right and imagining the roof and the windows in their finished splendor.

We then drove to Helmsley Castle where my younger daughter and I did all kinds of climbing on and around the earthworks.  It was a blast!  The photo below shows where we attacked the castle (click on the image for a larger view).

The castle shadow kept our attack from being discovered!  Once inside the castle grounds, I snapped a photo of the East Tower (click on the image for a larger view).
We loved the weather and the gorgeous green grass.  After a great night's sleep at The George and Dragon Hotel in Kirkbymoorside, we drove to Pickering Castle.  We were met by a lovely English Heritage host who gave us the rules off the bat:  no climbing!  My younger daughter and I were disappointed, but we understood that climbing would have meant disturbing birds' nests in the earthworks.  The photo below shows me near some castle ruins (click on the image for a larger view).
Our fourth and final destination was Byland Abbey.  I was thoroughly amazed by the size of the abbey.  I tried with the photo below to capture the size of the ruins, but there is so much more to the left of the photo that I didn't succeed (click on the image for a larger view).
Just look at the size of the cloister in the photo below (click on the image for a larger view).
I can think of several games that could be played on that much grass!  My daughters had fun racing along the edges.

A refreshing weekend away from work gave us the opportunity to explore beautiful parts of England and transform ourselves back to the 12th century.  All of the structures we visited thrived in centuries that followed the 12th, and thousands of people either called them home or passed through them on their travels.  We are glad English Heritage maintains these national treasures and allows visitors to England, like us, the chance to learn and experience the history in the country we call home for a year.

11 May 2016

Love Talking Research!

I had a great time earlier today giving a talk on my Tour de France research at Sheffield Hallam University.  The audience was gracious, asking lots of insightful questions during and after my talk.  A colleague snapped the photo below (click on the image for a larger view).
I so enjoy talking about my research and science in general.  I spoke about the successes we had modelling last year's Tour de France, as well as what we're looking forward to this year.  There are just 52 days to go before the Tour de France begins.  I can hardly wait!

10 May 2016

Talk at Sheffield Hallam University

On Wednesday, 11 May 2016, I will give a talk at Sheffield Hallam University on my Tour de France research.  The talk will be at 12:00 pm in A021 Collegiate Hall, between Collegiate Crescent, Broomgrove Road, and Ecclesall Road (bottom of the hill).  The talk is open to the public.  I'm looking forward to it!

04 May 2016

From Sports Detectives to Napoleon (and two stories in between)

It is a beautiful day in Sheffield right now.  The temperature is around 13 C (about 55 F), which feels great accompanied by a steady breeze.  My sabbatical journal has been a bit more sporadic than I originally thought, but that's fine.  It is what it is.  For now I'm enjoying life in Sheffield on a gorgeous spring day.  I spent 75 minutes working out at Ponds Forge this morning, followed by an hour teaching quantum mechanics to three of my tutorial students who showed up for an optional class.  Before getting back to the several upcoming talks I need to prepare for, I'll touch on a few items that have piqued my interest of late.

In May of 2015, I was flown up to New York City for three hours of interviewing for a show that is now on the Smithsonian Channel.  The show is called the Sports Detectives, and I provided sports physics commentary for a few of the topics that will be discussed during the six-part series.  For all the time I spent in front of a camera, the show will likely use just a few seconds here and there.  But that's okay by me!  Because I don't get the Smithsonian Channel here in Sheffield, my cousin was kind enough to send me a screen shot from this past Sunday's episode on Franco Harris' Immaculate Reception (click on the image for a larger view).
I'll have to wait until I return to the US in August to see the entire series.  But for now it's neat thinking about being on a television show for a few seconds.

The biggest sports story of the year just unfolded here in England.  Leicester City defied 5000-to-1 odds and won the Premier League Championship.  I've seen single-game upsets in my life that shocked me, but having a team with 5000-to-1 odds against it go through an entire season and win it all is something I've never seen.  I simply can't think of anything comparable in all the years I've watched sports in the US.  Check out the photo I took of the front page of the Metro I picked up on the bus yesterday morning (click on the image for a larger view).
Unless one has a rooting interest in another football club, who can't love this story?!?  Now if I had only put £20 on The Foxes at the beginning of the season ....

In other sports news, Sheffield once again played host to the World Snooker Championship.  The Crucible Theatre was the venue.  I confess that I know very little about snooker, but I couldn't help but get interested with the world championship being played in the city I currently live in.  I snapped the photo below a week before the tournament ended (click on the image for a larger view).
I love that topiary!  I'll miss seeing it when I walk from my bus stop to work in the morning.  Mark Selby won the championship, his second in the past three years.  I suppose it's only fitting that he was born in Leicester.  This is definitely Leicester's year!

It's certainly a worn book now.  But that's the best kind of book, isn't it?

This has been fun getting a few items off my mind and into a blog post today.  But now it's time to get back to talk preparations.  I'll write more on my upcoming talks in the not-too-distant future.

03 May 2016

Fun Place to Experience Sea Life

We spent May Day, the Early May Bank Holiday, at Sea Life in Manchester.  It was a great day!  There are reportedly over 5000 animals in the various tanks there, and I can believe it.  My wife, two daughters, and I thoroughly enjoyed seeing an incredibly diverse group of sea creatures.  My younger daughter was especially enthralled; she hopes to make a career with animals in another decade or so.  We learned a lot about the animals, including conservation efforts underway to help some of the more endangered species.  More than 70% of Earth's surface is covered with water.  It's not always easy to remember that we humans occupy less than a third of Earth's surface.

Of all the animals we saw, my favourite was Ernie, the giant green see turtle.  I snapped the photo below of Ernie swimming with lots of other animals (click on image for a larger view).
As we walked under the tank, we learned that Ernie is 11 years old, which is still quite young for a species used to living to almost a century.  Seeing so much sea life in one place really got us thinking about our very distant cousins.

Before hopping on the train from Manchester to Sheffield, I snapped a photo of this headline (click on image for a larger view).
I suppose everything is relative.  A temperature of 75 F (about 24 C) would be considered mild at this time of year in my Virginia hometown.  My hometown will in fact have temperatures comparable to 75 F today, but with thunderstorms helping to keep the day "cool."  Frankly, I'll take English weather any time!